Noise detector circuits are used in a variety of applications. Many noise detector circuits have been developed. Some noise detector circuits were developed for detecting noise on power lines. Other noise detection circuits were developed for detecting noise on radio signals. Unfortunately, many noise detector circuits designed to detect noise on power lines are not suitable for detecting noise signals that interfere with the operation of modem integrated circuits. Also, many noise detector circuits designed for detecting noise on radio signals are designed to detect noise only above a fixed threshold.